1. Field of the Invention
This invention relates generally to thermo-optic waveguide apparatus.
2. Related Art
Thermo-optic waveguide apparatus utilize heat to change the refractive index of an optically-transmissive structure, causing an optical path length for a source of light propagating through the structure to be increased. This optical path length change in turn causes a phase of the light propagating in the optically-transmissive structure to be changed. Such light propagating through the structure can then be combined with a source of light propagating elsewhere. Constructive and destructive interference between two such combined sources of light can be utilized as an optical on/off or dimmer switch, or as a tuner of an output wavelength. For example; a Mach-Zehnder thermo-optic interferometer apparatus may be formed based on these principles.
There is a continuing need for new types of thermo-optic waveguide apparatus designed for effective operation utilizing these thermo-optic principles.